1. Field of the Invention
The present invention relates to a clamping device for erect holding of thin work pieces and, in particular, to such a clamping device for enabling support of doors and the like on their edges and for making electrical outlets safely and conveniently available to enable carpentry work to be performed on such work pieces.
2. Description of the Prior Art
Recurring problems, which arise particularly in carpentry work, include the need to support work pieces, such as doors and sashes, on their edges so that work may be performed on them while they are held in a generally upright position and, in addition, to provide safe and easy access to electrical outlets so that power-operated tools may be used.
Many devices have been devised to address the former problem, and may be grouped into three catagories. The first is illustrated by U.S. Pat. Nos. 771,753, 849,354, 1,067,667 and 1,606,634, in which the door is simply clamped between a pair of jaws by moving them manually or with the aid of a screw mechanism into contact with the sides of the door followed by, if necessary, use of wing nuts to affix them in position. The second catagory is represented by U.S. Pat. Nos. 611,340, 848,837, 1,042,232, 1,138,088, 2,605,795 and 2,830,632, where the weight of the door brings the jaws into clamping contact with the sides of the door. The third includes U.S. Pat. Nos. 708,238 and 4,391,437, which employ a hook or a lever to close the jaws on the door. All these devices have one or more of the following shortcomings. Some require considerable manual effort in the clamping or unclamping operations. Others comprise a complex number of constituent parts which may be subject to malfunction or breakage, for example, by the weight of the work piece. In some cases, its weight might cause it to be jammed between the jaws and thereby to cause excessive squeezing of or injury to the door and possible indenting or marring of its sides and to prevent its facile removal from the device. Still others need to be supported on a substantially flat surface as a condition for enabling their operability.
With respect to the latter safety problem, it is conventional to extend a long extension electrical cable from an electrical outlet and, when one tool is to be used in place of another, the last used tool is unplugged and the new tool is connected to the cable in its place. In an alternate approach, a plurality of tools are plugged into a multiple female plug at the end of the cable extension or a jumble of electrical cords are extended to the outlet. Regardless of the particular set-up, all have safety hazards, either in exposing the user to electrical or physical harm. Merely having a plurality of electrical cords in the work area presents the possibility of injury to him should he trip and fall if his feet become entangled with even one cord. A plurality of cords also increases the likelihood of electrical shock.